Girls can do anything they put their minds to! Seriously, have you seenthis video? And if they don't believe it, you best tell them otherwise.

Naturally, that's the path Leah Calvert and her ex Corey took when their baby girl uttered three words that no kiddo should ever say: "I'm not strong." In the "Teen Mom 2" sneak peek, below, Corey tells his baby mama that four-year-old Aliannah, who has a rare form of muscular dystrophy, made the less-than-uplifting comment just recently. Corey recounts that he tried buoying the little girl, telling her, "You are strong, and you can do whatever you want to do." Leah agrees, saying it's a parent's job to lift their kids up.

Here's hoping that was little more than a temporary setback for Ali, seeing as she and her twin sister Aleeah seem to be back at it, dreaming big! Leah recently tweeted about the girls' very ambitious career goals: "When al grows up she wants to be a Doctor just like mommy wanted to be and aleeah wants to be a nurse! #nothingisimpossible."